Securing the information to exchange is an important aspect of communication nowadays; sensitive data must be kept secret from unauthorized persons. Accordingly, many techniques and systems have been developed with this objective in mind. Some techniques relate to securing communication means while others relate to securing the data communicated. The prior art that is the most worthy of mention in accordance with the present invention consists of the two following documents.
The first prior art, “PUBLIC KEY INFRASTRUCTURE (PKI) BASED SYSTEM, METHOD, DEVICE AND PROGRAM”, developed by Asanoma et al., is available as U.S. publication No. 2003/0056099. This U.S. patent publication discloses a system for the distribution of smart cards (a.k.a. IC cards) that includes an authentication certificate and encryption/decryption capabilities based on a public key and a secret key. The system described in the present document has the advantage, over the prior art, of saving time and labor involved in the collection and redistribution of smart cards done in order to update a private key and a public certificate.
The second relevant prior art worthy of mention is “INFORMATION PROCESSING SYSTEM HAVING FUNCTION OF SECURELY PROTECTING CONFIDENTIAL INFORMATION”, developed by Shimizu et al., and available as U.S. Pat. No. 6,085,323. This U.S. patent discloses an encryption system wherein the encryption process is completed by two distinct devices. A first device, namely a computer, establishes a first encryption key and encrypts sensitive data with this first key. The first key is transmitted to a second encryption device, namely a smart card, which encrypts the first key with a second encryption key and transmits the encrypted first key to the first encryption device. The first encryption device is also composed of correlation storage means for correlatively storing the encrypted sensitive data and the encrypted first key.
Although the above prior art provides a certain level of security for sensitive data and efficient certificate management, further improvement is desirable in these fields of technology.